Home » Alerts » How to Fix Norton Product Error “8505 and 129”

The very first step to fix Norton error 8505, 129 is, restart your computer. If the problem still persists, you have to check your Network proxy settings and run an advanced scan to locate and remove potentially unwanted applications with the help of Norton Power Eraser.


Step 1: Check the Network proxy settings

  • Press the Windows + R keys together to open the Run dialog box.
  • Type in the text “inetcpl.cpl” and press Enter.
  • It’ll launch Internet Properties window on your computer.
  • Click LAN settings on the Connections tab.
  • Under Proxy server in the Local Area Network (LAN) settings dialog box, ensure that none of the check boxes are selected.
  • If you find any entries under Proxy server, uncheck the boxes and choose Automatically detect settings.
  • You must run an advanced scan on your PC with Norton antivirus removal tool because unknown proxy server address can be a signal of potential threat or unwanted application.
  • Click OK.
  • Click on the option Apply and then click OK.

If the problem still persists, go to step 2 and follow instructions.

Step 2: Configure network connection settings on Windows

  • Press the Windows + letter R keys to open the Run dialog box.
  • Type the text “ncpa.cpl” in the Run dialog box, and then click OK.
  • Right-click the currently active network adapter then click Properties.
  • Click on the option Yes or Continue when the User Account Control prompt appears.
  • In the Network Connection Properties window, Click Internet Protocol (TCP/IP) or Internet Protocol Version 4 (TCP/IPv4) under “This connection uses the following items” options.
  • Click Properties.
  • Click Use the following DNS server addresses to specify DNS server address settings.
  • Type the two Norton ConnectSafe IP addresses: Preferred DNS: and Alternate DNS: in the Preferred DNS server and Alternate DNS server boxes.
  • In the Internet Protocol (TCP/IP) Properties window, click OK.
  • Again click OK.

If the problem adheres, run a scan with Norton Power Eraser in step 3.

Step 3: Run the Norton Power Eraser – Unwanted Application Scan

  • Download Norton Power Eraser tool.
  • Click Save.
  • Select the Desktop location, and then click Save.
  • Double click the NPE.exe file, to run Norton Power Eraser.
  • Click Yes or Continue when the User Account Control window prompts.
  • Read the license agreement, and click Accept to continue.
  • Click the Unwanted Application Scan icon in the Norton Power Eraser window.
  • The results are displayed in the Unwanted Apps Scan Complete window when Norton Power Eraser completes the scan.
  • In the Unwanted Apps Scan Complete window, click Uninstall next to the unwanted application or toolbar.
  • Follow the on-screen instructions.
  • Restart the computer when Norton antivirus uninstall process completes.

If the issue still remains, find out the unwanted toolbars that are usually bundled with specific free programs that you have installed on your PC.